Apparatus for and method of making fiber board



Sept. 19, 1933. E. T. STREET 1,927,378

APPARATUS FOR AND METHOD OF MAKING FIBER BOARD 5 Sheets-Sheet 2 E. T. STREET APPARATUS FOR AND METHOD OF MAKING FIBER BOARD Flled oct 23, 1951 i z 37 /z .l f

Sept. 19, 1933.

E. T. STREET Spt. 19, 1933.

' APPARATUS FOR AND METHOD oF MAKING FIBER BOARD Filed Oct. 25, 1931 5 Sheets-Sheet 5 5 Sheets-Sheet 4 E. T. STREET APPARATUS FOR AND METHOD OF MAKING FIBER BOARD Filed oct. 25, 1951 Sept. 19, 1933.

Sept. 19, 1933. E, Tl STREET 1,927,378.

APPARATUS Fon AND METHOD 0F MAKING FIBER BOARD Filed 0G12. 23, 1931 5 Sheets-Sheet 5 gwn-kot Patented Sept. 19, 1933 NITED STATES PATEN FFHCE Edward T. Street,

Downingtown, Pa.

Application October 23, 1931. Serial No. 570,708

33 claims.

This invention relates to machines for the continuous manufacture of liber boards, particularly boards of the type known as wallboard which are utilized widely in building and construction operations for lining and insulating buildings and for analogous purposes.

Various types of these continuously operating machines have been heretofore designed-or suggested, and a number have been placed in actual use. Generally' speaking, each such machine comprises two essential parts, a foraminous member, generally endless as in the case of a drum or elongated forming wire, and stationary means for maintaining in contact with the surface of such member a body of pulp stock. The liquid of the pulp stock flows through the openings of the foraminous forming member, and the fibers are ,deposited on its surface, gradually building up a board which, when the forming m'ember passes from the vicinity of the pulp stock retaining means, is of the desired thickness and may thereafter be removed from the machine.

A type of such machine which has proven eminently satisfactory in practice is disclosed in the copending application of Jacob Edge, Serial No. 558,591, filed August 21, 1931. In that machine the foraminous member comprises an elongated forming wire disposed over a plurality of rollers, the upper reach of the wire, which is that portion which is for the time being performing board making functions, being disposed in a generally horizontal direction and the means for maintaining the pulp stock in contact therewith comprising a chamber positioned above the upper reach of the forming wire and of which the forming wire comprises the bottom, the chamber walls being of such height that the pulp stock above the forming wire is maintained at a relatively high static pressure.

The present invention contemplates a number of improvements upon machines of this general type primarily intended to bring about a more efficient operation of the machine and the pro- 45 duction of more perfect board. Thus, in accordance with the present invention, an improved m'eans is provided beneath the pulp stock chamber for supporting the forming Wire, particularly the edges of the Wire which ordinarily, in passing beneath the chamber, are subjected to considerable Wear in the normal operation of the machine.

The invention further includes means posi tioned Within the pulp stock chamber for preventing excessive depositi-on of fiber on or toward the edges of the wire, it having been found that with the ordinary machine there is a tendency for excessive deposition of fibers along the margins of the forming surface, thus causing the production of boards having unduly thickened edges.

Again, the invention contemplates the provision of means, at the point Where the forming wire passes from beneath the pulp stock chamber, for facilitating the removal of the forming wire and pulp layer deposited thereon with permitting the escape of any of the pulp stock. f

An important feature of the invention resides in the provision of a means for and method of removing from the layer of pulp fiber on the forming wire, just prior to the'time when the pulp layer emerges from the pulp stock chamber, the major portion of the water which it contains. At this point the pulp layer is relatively deep and entirely saturated with liquid. The pulp stock layer passes through a vertically restricted aperture in emerging from the pulp stock chamber, its thickness is reduced, and a large proportion of the contained liquid is expressed. This expressed liquid is prevented by member 22 from directly 80 escaping and must nd its Way, through the fibers, to the surfaces of the board and escape as the thickness of the pulp layer is decreased, and this flow of liquid tends to washchannels through the pulp layer, the washing effect increasing as the speed of the forming Wire increases. This action is not noticeable at the under surface of the board as this side is confined only by the forming wire, and liquid may make its escape freely at every point of the board surface. But the upper bers rest only lightly in position and are easily dislodged by the upward and rearward (relatively to the board) movement of the liquid.

The invention provides means, cooperating with that wall of the forming chamber which is chiefly instrumental in reducing in thickness the layer of pulp, whereby the outflow of liquid is directed and controlled, so that serious disarrangement of the uppermost fibers o f the board is prevented. This same means also permits the operator to have a substantial measure of control over the superficial appearance of the upper surface of the board as it enables him to so effect the arrangement of the uppermost or visible fibers of the top of the board that the appearance of the same may be either striped or uniform as desired.

The invention includes numerous other improved features of construction. as will be apparent to one skilled in the art. One embodiment of the invention is illustrated in the accompanying drawings and will be hereinafter described in detail. It will be appreciated, however, that this particular embodiment is set forth by way of example only and that the novel and improved features of construction may be incorporated in machines which vary widely in appearance, type, and details of design.

In the drawings:

Figure 1 is a side elevation of a complete machine for the manufacture of ber boards, the various improvements which I have perfected being incorporated therein;

Figure 2 is a longitudinal vertical section through the machine, a few details being omitted for the sake of clarity;

Figure 3 is a side elevation of a portion of the machine on a larger scale;

Figure 4 is a top plan view of that portion of the machine illustrated in Figure 3, a showing of a portion of the top of the machine having been omitted, however, in order that certain of the interior details might be more clearly perceived;

Figure 5 is a longitudinal vertical section through the portion of the machine shown in Figure 3;

Figure 6 is a section on line 6-6 of Figure 5;

Figure 'l is a partial section on line 7 7 of Figure 5;

Figure 8 is a partial section on line 8--8 of Figure 5;

Figure 9 is a full section on line 9--9 of Figure 3;

Figure 10 is a full section on line 10-10 of Figure 2;

Figure 11 is a longitudinal section, on a relatively large scale, through a portion of the pulp stock chamber, showing the means for facilitating and controlling the escape of water or other liquid from the pulp layer as its thickness is reduced; and

Figure 12 is a section on line 12-12 of Figure 11. The principal portions of the machine cornprise, as has been heretofore pointed out, the endless foraminous forming member and the stationary pulp stock chamber, and in the drawings the forming wire or member is indicated at 10, and the pulp stock chamber is generally indicated at 11. Both are supported upon a suitable frame generally indicated at F, and this frame may vary widely in design and construction in adapting the invention to various sizes and types of machines. From Figure 1 of the drawings, it will be -seen that the frame comprises a horizontal portion 12 and\a number of vertically extending legs indicated at 13. The legs support longitudinally extending parallel side beams or girders 14 which may have any desired shape and may vary in specific details at various points along the machine. As may be seen from an inspection of Figures 7 and 8, these side frame members comprise channel irons at the points along the machine at which these sections were taken. I

The endless forming wire 10 is supported uponrollers in such manner that its upper reach is disposed horizontally and substantially in the plane of the top of the frame, and its lower reach is beneath the frame. It passes successively over the breast roll 15, the plurality of parallel closely spaced table'rollers 16, the bottom series 17 of a set of pressure rollers, the table rollers 18, the bottom primary press roll 19, the bottom press roll 20, and the several guide and stretch rolls 21,

21. By adjusting the guide and stretch rolls, the proper alignment and tension of the wire can be easily maintained. When operating, the wire is continuously moved at a uniform rate in the direction of the arrow A (Figure 2), and each section of the wire successively passes beneath chamber 11, the portion of the forming wire which is for the time being resting upon the table rollers 16 actually comprising the bottom of the pulp stock chamber.

The level of the pulp stock in chamber 11 is maintained relatively high, for instance, at approximately the point indicated by the numeral 79 in Figure 2, so that the liquid has a relatively high static pressure at the surface of the wire. The liquid passes through the interstices of the wire, falls beneath the frame, and is collected and removed. The fibers themselves are `caught upon the surface of the wire, and a considerable layer of such fibers is built up upon each successive section of the forming wire as it passes beneath the pulp stock chamber.

It will be observed that the pulp stock chamber has a substantially vertically extending portion which is indicated by the numeral 1l and a forwardly extending portion 112, the side Walls of which are parallel to each other and to'the edges of the forming wire, and the top wall of which is forwardly and downwardy inclined, terminating in a transverse edge relatively close to the wire. The extreme lower end portion of this inclined top wall comprises a movable member 22 lhaving its longitudinal edges secured by means `of angle irons 23 to two vertically adjustable and vertically disposed plates 24. The outer faces of these plates slidably engage, respectively, the flat inner surfaces of plates 25 rigidly secured to the frame, and the lower edges of plates 24 are received in slots defined by the inner surfaces of stationary plates 25 and the filler blocks F rigidly secured to these plates, respectively. The lateral edges of movable member 22 thus make liquid-tight contact with the side plates 25 of the pulp stock chamber.

Member 22 as an entirety is hung from longitudinally'extendlng levers 30 by any suitable suspending devices, levers 30 having their ends pivotally mounted upon the transversely extending rock shaft or arbor 31, member 22 and levers 30 rising and falling in unison in the operation of the machine. The forward edge of member 22, which is indicated at 22', is s o positioned relatively to the forming wire that the upper fibers of the layer of pulp which is passing from the forming area are moved downwardly and the thickness of the layer greatly decreased. The upper edge of member 22 maintains close contact with the forward edge of the inclined topplate 112 of the pulp stock chamber so that no leakage of pulp stock liquid takes place` at the junction of these two members.

It is deemed advisable, if not essential, to provide means adjacent the edges of the forming wire to confine the pulp stock and prevent free outflow of the same laterally of the layer of pulp as it passes from the pulp stock chamber.y One of these devices may be clearly seen in Figures 5, 6, '7, and 8. It comprises two curved, forwardly tapering, exible blades indicated at 32 and 33 respectively, one of these blades being attached as by bolts 34 to plate 24, which is vertically movable, and the other being attached as by bolts 35 to the side plate 25 of the machine. The space between the blades and the side plates of themachine is lled with sponge rubber indicated at 37.

and in the operation of the machine the blades maintain close contact with each other throughout practically their entire lengths, comprising in reality, when taken with the rubber Abacking 37, a vertically extensible and contractible device which at all times substantially llsthe space to the sides of the pulp layer on the forming wire. The filling of sponge rubber is particularly useful in preventing leakage through the spaces above and below blades 32 and 33 and beyond the edges of the Wire.

In Figures 5 to 8, inclusive, member 22 is shown in a highly elevated position, which position it would not normally occupy while the machine is in operation but only when the machine is not in operation and is being cleaned, repaired, or inspected. With themachine in actual operation, the forward edge 22' of member 22 is much closer to the forming wire and the rollers 51 and upper blade 32 also lowered, as shown in Figure 11, these several parts being raised or lowered in unison, and hence the blades 32 and 33 are, under such conditions, in contact with each other substantially throughout their entire lengths. These blades are preferably fabricated of spring metal, which metal is resistant to the action of the pulp stock so as not to rust, and are suiciently flexible to permit of lateral yielding movements to a slight extent, due to sligoht variations in the pressures exerted against them by the edges of the pulp layer.

The free end of the inner blade 32 engages the side plate 24and may be adjustably connected to such plate by a pin and slot connecting means, indicated at 32'. With both ends of blade 32 positively held, the blade will be rather rigidly supported, which is desirable with some materials, but connection 32 may be released whenever desired. When the end of blade 32 is positively attached to member 24, this blade will press against the edge of the fiber layer to a definite degree instead of exerting a yielding pressure. As will be seen clearly from Figure 8, the free end of the inner blade 32 has its lower edge disposed closely above the surface of the forming wire. As the upper blade is vertically movable and is secured to plate 24 by bolts, it is desirable to form a pocket or recess 25 in plate 25 in which the bolt heads may be received. The lower or operative position of blade 32 is indicated in dotted lines in Figure 8.

By the means just described, a layer of pulp may be continuously removed 'from beneath the pulp stock chamber Without loss of pulp stock liquid, and in general this means may be said to comprise an orifice of a flexible type, having a top wall which may be adjusted vertically, and laterally spaced, vertically extensible and contractible devices for filling at all times the spaces at the edges of the pulp layer through which pulp stock would otherwise be free to escape.

After passing the lower edge 22 of member 22, the forming wire moves over the lower series of a set of pressure rolls 17, thence over table rollers 18 and press rolls 19 and 20, and is removed from the `forming wire at the point R in a board-like but still moist condition. A foram'inous member or pressure wire is indicated at 50, this wire moving in the direction of the arrow B shown in Figure 2, the lower reach of this wire being disposed in substantial parallelism to the upper reach of the forming wire, passing beneath the upper series 5l of a series of pressure rollers positioned vertically above, respectively, the rollers of 'series 17, thence beneath the upper primary press roll 52, around the top press roll 53, and over t e guide and stretch rolls 54, 55, 56, and 57. Roll 57 is supported at its end upon the levers 30 and will therefore follow the movements of member 22.

Wire 50, after passing around roll 57, passes beneath memberv 22 through'a slot 58 formed in this member immediately below the roller 57. The wire 50, therefore, enters the pulp stock chamber and moves downwardly along the under surface of the movable member 22, coming into contact with the layer of pulp stock which has been formedupon the forming wire and remaining in contact with the upper surface of this layer as the layer is subjected to pressure by means of the pressure rollers 17 and 5l, the primary press rolls 19 and 52, and the top and bottom press rolls 20 and 53. The top wire thus described connes the pulp during the period when it is being subjected to repeated pressure, prevents adherence of the pulp to the surfaces of the upper pressure rollers, and tends to form a highly satisfactory upper surface on the board being fabricated. The most important function of wire 50 is, however, to hold firmly the nascent ber layer as it is being gradually compressed, that is, while passing from a line approximately through bolts 34 to the pass between the rst pair of rolls 17 and 51.

Levers 30 are pivotally connected at 60 to a frame 6l upon which the ends of the rollers v5l are journaled. Hydraulic cylinders are indicated at 62, and the pistons of these cylinders are connected by rods 63 with the free ends of levers 30. By means of these cylinders the first roll 51 and the plate 22 may be drawn downwardly with the desired pressure. A second pair of cylinders 62 has its pistons connected tothe ends of frame 61 so-that the pressure of the remaining rolls 5l against the formed board may be regulated as desired. By means of hydraulic cylinders 62 and 62 a desired constant pressure on the board may be maintained, regardless of slight variations in thickness. Member 22 and roll 57 follow the movements of the rst primary press roll 51, both members being hung from levers 30, as previously explained, and levers 30 being pivotally connected to frame 61. By operation of the hydraulic cylinders, therefore, the movable parts may be adjusted to any desired position.

The table rollers 16 are supported at their ends in individual bearings 64 which are mounted upon brackets resting upon the frame of the ma chine. The edges of the forming wire extend laterally beyond the ends of the cylindrical surfaces of the rollers and rest upon wear plates indicated at 66, these plates being rigidly securedto the frame of the machine in horizontal positions and so that their upper surfaces are in the plane of the upper elements of the series of table rollers.

In order that the wire 10 may have maximum support adjacent its edges and also in order to minimize the wear of the wire due to the drag of the wire on plates 66,-the edges of the plates are provided with extensions 6G which project outwardly over the edges of the rollers and partially into the gaps or spaces between the rollers. This not only provides additional support for the Wire, but the serpentine edges of the supporting `plates minimize wear on the bottom of the wire by causing the wear to take place over a wide band instead of along a straight line, as would be the case were tle edges of the supporting plates 66 parallel to the path of movement of the wire.

A feature of the invention consists in the design of the side walls of the pulp stocs chamber. As may be observed from Figures 1 and 10, the side walls of the pulp stock chamber are formed in two portions, the first portion comprising the top plates, generally indicated at 76), and the second portion comprising panels 7l. The top plates are supported by brackets 72 directly from the frame of the machine, and the lower plates or panels are secured in position independently as by means of bolts 73. These bolts are accessible from the outside of the machine so that any one of these panels "Il may be removed for the purpose of inspecting, cleaning, or repairing the table roller bearings, plates 66. or the forming wire 10.

As most clearly seen from Figure 1G, the plates 71 are downwardly and outwardly inclined so that, the edges of the forming wire lie, in effect, in pockets formed in the side walls of the pulp stock chamber. This construction prevents any substantial deposition of ber on the margins of the wire or, to put it differently, retards deposition of fiber on the margins of the wire. The angles of inclination of members 7l should be in the neighborhood of 45", as shown, with the horizontal. Should this angle be materially less, fiber will wedge in over the edge of the wire, and, should it be materially greater, the edge of the sheet will be unduly thickened. Beneath the vertically movable member 22 and in rear of the lateral devices comprising blades 32 and 33 and sponge rubber 37 (see Figure 9), the side walls of the pulp stock chamber are vertically disposed, and forwardly tapering filler blocks 'l5 are secured thereto, these ller blocks overhanging the margins of the forming wire and thereby continuing the protection against substantial fiber deposition on these margins afforded to the wire by the overhanging plates in the rear portion of the pulp stock chamber. The filler blocks are removable.

Any suitable means maybe provided for supplying the pulp stock chamber with the pulp stock, and from Figure 2 of the drawings it will be seen that I provide a simple inlet trough or duct 76 which discharges into the pulp stock chamber ll near the top. The pulp stock passes by a series of baies "I7 before entering that portion of the chamber which overlies the forming wire. The chamber is so designed that the fibers of the pulp stock fall vertically onto the forming wire at all points therein, the decrease in section in the chamber insuring equal forward flow of the pulp stock at all points therein, it being obvious that the vertical flow of pulp stock liquid through the forming wire decreases in rapidity as the thickness of the ber layer increases.

In some instances, however, it may be necessary to provide one or more agitating devices in the pulp stock chamber, at points therein where the forward flow is not great, in order to maintain the density of fiber content of the pulp stock the same throughout. Also, where the pulp stock contains fibers of different types, the agitators prevent segregation of such types. One such agitating device is shown in Figure 10 and is seen to comprise a transverse shaft 80 having a series of disks 81 positioned thereon and disposed at angles to the axis of the shaft. One end of the shaft passes through the side walls 70 of the chamber and has secured thereon a sprocket 82,

by means of which the shaft may be rotated from reggeva any suitable source of power, :for instance by an electric motor. The effect of the rotation of shaft 80 is to cause local agitation of the pulp stock surrounding the same, which agitation serves to maintain the fibers in suspension. such agitating devices may be provided or any other well-known agitatingl device employed to bring about this result.

n the normal operation of the machine, the speed of the forming wire is so regulated that a relatively deep body of fiber is deposited on each section thereof by the time such section reaches the forward end of the pulp stock chamber. This layer comprises a very large proportion of pulp stock liquid, generally water, which should be removed from the pulp so far as possible before the pulp layer passes from the pulp stocls chamber. To bring this about, the forward edge 22 of member 22 is disposed closely above the` forming wire so that the marginal portion of its lower surface constitutes, together with the upper wire, means for depressing the upper fibers and compacting the layer, as well as means for holding back the pulp stock. (See Figure l1.) During this compacting of the nber layer, a consid erable amount of its lcontained water will be forced outwardly through the forming wire, but a considerable proportion will tend to flow upwardly and rearwardly along the lower surface of plate member 22 and to wash channels in the upper surface of the pulp layer unless means is provided for permitting the escape of controlled amounts of pulp stock liquid at this point. Such a means is disclosed in Figures l1 and 12.

The forward margin of plate member 22 isL provided with a plurality of slots 85 so positioned as to permit the direct escape of water, or other pulp stock liquid, from that portion of the pulp layer which is then undergoing the compacting operation, to the outside of the pulp stock chamber. A box 86 is positioned on the upper side of member 22 for receiving the water thus permitted to escape, and one or more conduits 87 are provided for conducting away this liquid. A valve 88 controls the rate of escape of liquid through slots 85, and this valve is regulated so that the desired rate of escape is obtained. Care is taken to prevent the escape of liquid throughslots 85 at too fast a rate, as this would result in the formation of a compact fiber layer upon the upper wire, and the resulting board would be laminated and weakened. A proper adjustment of valve 88, however, permitting the direct escape from the pulp layer of the proper quantity of liquid, results in the formation of boards having homogeneous structures throughout and without grooves or washouts in its upper surface.

By arranging the apertures or slots 85 in various ways, the superficial appearance of the upper surface of the board 'may be controlled to a certain extent, the precise shape and arrangement of the apertures apparently having some controlling influence upon the orientation of the top surface fibers. With the arrangement of slots shown in Figure 12, the surface of the board will be found to be uniform throughout, but, should the elongated transverse slot 85x1 be omitted, the upper surface of the board will be found to be longitudinally striped. Other arrangements of apertures will produce stripings which vary in character. The method and means just described provide, therefore, a way of effecting the ornamentation of one surface of the board,

if such ornamentation is desired.

The pulp stock and pulp stock liquid which Additional fall through the forming wire in the normal operation of the machine are caught in three separate basins or pans, indicated at 90, 91, and 92 in Figures 1 and 2. Pan 92 underlies that portion of the forming wire which is immediately below the main portion 11 of the pulp stock chamber and which has just passed into the 'forming area. As itv passes over the roller 15 and into the forming area, the Wire is clear of ber, and hence a large quantity of pulp stock liquid freely passes through, carrying with it certain of the neror shorter bers of pulp. This pulp stock is of low concentration but nevertheless valuable for the iiber it contains and hence is returned by any suitable means, as by a pump, to the pulp stock chamber. The catch basin 90 beneath the forward end of the pulp stock chamber and the pressure rollers likewise is provided with means to return the liquid caught therein to the chamber 11 as it has been found that liquid falling from the wire at this point also contains a considerable amount of valuable fiber. The liquid falling into catch basin 91, however, is practically clear of ber and may either be discharged as waste, returned in part to the forming chamber, or sent back to the stock preparing system. Oitake conduits for the several catch basins are indicated at 90', 91', and 92' in Figures 1 and 2, but the pumps and piping connections have been omitted for the sake of clarity.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent iszl. In a board making machine, in combination, a frame, means on the frame for supporting the horizontally disposed reach of an endless longitudinally movable forming wire, and an elongated chamber above the forming wire for maintaining a body of pulp stock upon the upper surface of the forming wire, the side walls of said chamber having removable sections at about the plane of the forming wire, for the purpose set forth.

2. In a board making machine. in combination, a frame, means on the frame for supporting the horizontally disposed reach of an endless longitudinally movable forming wire, an elongated chamber above the forming wire for maintaining a body of pulp stock upon the upper surface of the forming wire, and brackets for rigidly supporting the chamber from the frame, said brackets being connected to the chamber walls, respectively, at points above the forming wire, and the chamber walls intermediate said points of support and the forming wire comprising removable panels whereby access may be had to the interior oi. the chamber from the side without disconnecting the brackets and chamber' side walls.

3. In a board making machine, in combination, ar frame, anV endless forming wire, a series of rollers mounted on the frame and disposed in a horizontal plane for supporting one reach of the forming wire, an elongated chamber above the rollers and forming wire for maintaining a body of pulp stock upon the upper surface of the forming wire, and means for supporting said chamber comprising a plurality of brackets having their lower ends secured to the frame and their upper ends attached to the walls of the chamber at points spaced above the forming wire, portions of the chamber side walls below the points of attachment of the brackets thereto being detachably secured in position and comprising elongated removable panels, for the purpose set forth.

V4. In a fiber board making machine, in combination, a forming wire supported for movement in a substantially horizontal plane, the edges of said wire being parallel to each other and to the direction of movement of the wire, and a chamber positioned above the wire for maintaining on the surface of 'the wire a body of pulp stock, the side walls of said chamber having portions overhanging the edges of the wire, for the purpose set forth.

5. In a fiber board making machine, in combination, a forming wire supported for movement in a substantially horizontal plane, the edges of said wire being parallel to each other and to the direction of movement of the wire, and a chamber positioned above the wire for maintaining on the upper surface thereof a body of pulp stock under static pressure, said cham-- ber having means overhanging the edges of the wire, and the wire forming the bottom of the chamber.

6. In a ber board making machine, in combination, a forming Wire supported for movement in a substantially horizontal plane, the edges of said wire being parallel to each other and to the direction of movement of the wire, and a chamber positioned above the wire for maintaining on the upper surface thereof a body of pulp stock under static pressure, said chamber having side walls extending in the direction of movement of the wire, the upper portions of said side walls being above the wire and the lower portions displaced outwardly beyond the edges of the wire.

'7. In a fiber board making machine, in combination, a forming wire supported for movement in a substantially horizontal plane, the edges of said wire being parallel to each other and tothe direction of movement of the Wire, and a chamber positioned above the wire for maintaining on the upper surface thereof a body of pulp stock under static pressure, said chamber having side walls parallel to each other and to the direction of movement of the wire, the upper portions of said side walls being vertically disposed and positioned to overhang the marginal portions of the wire, and the lower portions of the side walls adjacent the edges of the wire being .oiset outwardly to provide recesses Within which the edges of the wire are located.

S. The combination set forth in claim 7 in which the oiset lower portions of the side walls are detachable and removable to provide access to' the' interior of the chamber.

9. In a fiber board making machine, in combination, a horizontally supported and movable forming wire and a stationary chamber above the wire and of ywhich the wire forms the bottom, said chamber being adapted to maintain upon the u'pper surface of the wire a body of pulp stock under static pressure and having, at the endthereoi from which the forming wire passes, means adapted to prevent the escape of pulp stock from the chamber while permitting egress of the wire and the pulp layer thereon, 4said means engaging both the top surface and edges of the pulp layer.

10. In a fiber board making machine, in combination, a frame, a forming wire supported on the frame for substantially horizontal movement, and a stationary chamber positioned above the wire and of which the moving wire forms the bottom, said chamber being adapted to maing tain upon the upper surface of the wire a body of pulp stock under static pressure and having,

at the end thereof at which the forming Wire makes its egress, means adapted to prevent the escape of pulp stock from the chamber while at the same time permitting the egress of the forming wire and the layer of pulp deposited thereon, said means having a member maintaining contact with the upper surface of the pulp layer on the Wire and devices positioned adjacent the margins of the wire for engaging the edges of the pulp layer.

11. In a iiber board making machine, in combination, a frame, a forming wire supported on the frame for substantially horizontal movement, and a stationary chamber positioned above the wire and of which the moving Wire forms the bottom, said chamber being adapted to maintain upon the upper surface of the wire a body of pulp stock under static pressure and having, at the end thereof at which the forming wire maires its egress, means adapted to prevent the escape of pulp stock from the chamber While at the same time permitting the egress of the forming wire and the layer of pulp deposited thereon, said means having a member to maintain contact with the upper surface of the pulp layer on the wire and devices for yieldabiy engaging the edges of the pulp layer.

`12. In a flberboard making machine, in combination, a frame, a forming wire supported on the frame for substantially horizontal rnovefn ment, and ,a stationary chamber positioned above the wire and of which the moving wire forms the bottom, said chamber being adapted to maintain upon the upper surface of the wire a body of pulp stock under static pressure and having, at the end thereof at which the forming wire makes its egress, means adapted to prevent the escape of pulp stock from the chamben while at the same time permitting the egress of the forming wire and the layer of pulp deposited thereon, said means having a movable member adapted to maintain constant contact with the upper surface of the pulp layer on the wire and vertically extensible and contractible devices at the sides of the pulp layer for maintaining contact with the edges thereof, vertical extension or contraction of said devices occurring upon, and simultaneously with, movements of said member.

13. The combination set forth in claim 12 in which each such device comprises two resilient elements, one being secured' to the frame and the other connected to said member.

14. The combination set forth in claim 12 in which each such device comprises two relatively movable flexible blades positioned to maintain sliding contact with each other, one blade being connected to said member and the other to the frame.

15. The combination set forth in claim 12 in which each such device comprises two relatively movable flexible blades positioned to maintain sliding contact with each other, one blade being connected to said member and the other to the frame, said blades extending outwardly from the side of the chamber toward and over the forming wire.

16. The combination set forth in claim 12 inA whicheach such device comprises two relatively movable flexible blades positioned to maintain sliding contact with each other, one blade being connected to said member and the other to the frame, said blades'extending outwardly from the side of the chamber toward and over the forming asevera wire, and a filler of sponge rubber in the space between the blades and side of the chamber.

17. In a fiber board making machine, in combi= nation, a frame, a forming wire supported on the frame for substantially horizontal movement, a stationary pulp stock chamber above the wire and of which the moving wire forms the bottom, said chamber having substantially parallel side walls and a top wall which slopes downwardly in the direction of movement ofthe wire and terminates in means for restraining outflow of pulp stool; from the chamber, and tapering filler bloclrs positioned within the chamber at the sides thereof and adjacent said means, the filler blocks over 'hanging the margins of the forming wire.

i8. In a liber board making machine, in combi-` nation, a frame, a forming wire supported on the frame for substantialy horizontal movement, a pulp stock chamber positioned above the wire and of which the wire comprises the bottom, a

series of rollers adjacent the outlet end of said chamber over which the forming wire passes, a second series of pressure rollers positioned above said iirst mentioned series and above the forming wire, and uid pressure operated means for adjusting the position of the said second series of rollers relatively to the rst'series and the forming wire.

i9. 1n a fiber board making machine, in combination, a frame, a series of rollers mounted on the frame and arranged in parallelism, a forming Wire resting on said rollers and movable nonI mally to the axes of the rollers, the edges of the wire extending beyond the ends of the rollers, and plates mounted on the frame beyond the ends of the rollers for supporting the edges of the wire, thev inner edges of said plates being cut away at intervals, for the purpose set forth.

20. In a ber board making machine, in combination, a frame, a series of rollers mounted on Mill lill@ mit the frame and arranged in parallelism, a form wire, the upper surfaces of said platesbeing in the plane of the upper elements of the rollers and portions of the plates projecting into the spaces between the upper surfaces of the rollers.

21. In a ber board making machine, 4in combination, a frame, a series of rollers mounted on Ythe frame and arranged inparallelism, a forming wire resting on said rollers and movable normally to the axes of the rollers, the edges of the wire extending beyond the ends of the rollers. and plates mounted on the frame beyond the ends of -the rollers for supporting the edges of the wire,

the inner edges of said plates being scalloped, for the purpose set forth.

22. In a liber board making machine, in combination, a forming wire movable in a generally horizontal direction, and a chamber for maintaining upon the upper surface of 'the forming wire ay body of pulp stock; whereby a layer of pulp stock is deposited on the wire as it moves, said chamber including means for compacting the layer of pulp fiber on the wire just prior to its issuance from the chamber and means for releasing pulp stock liquid from that portion of the pulplayer which is being compacted, directly to the exterior of the chamber, during the come pacting operation.

23. The combination set forth in claim 22 in tti@ which means is provided for regulating the rate of flow of liquid released.

24. The combination set forth in claim 22 in which said pulp compacting means comprises a wall of the chamber which is downwardly and forwardly inclined and terminates in a horizontal edge parallel to the plane of the wire, and the liquid releasing means comprises one or more apertures formed in said member near the edge thereof.

25. In a ber board making machine, in combination, a pulp stock chamber and movable forming wire, said chamber having a stationary member adapted to press upon a layer of pulp on the wire just prior to its egress from the chamber, and means for permitting direct ow of liquid from the pulp layer, at the point where it is being compacted, directly to the exterior of the chamber.

26. In a ber board making machine, in combination, a pulp stock chamber and forming wire movable in a Xed path, a stationary member for compressing the pulp layer on the forming wire as it passes said member, said member permitting the direct flow of liquid therethrough whereby liquid may freely flow from the pulp layer during the compacting operation.

27. In a ber board making machine, in combination, a movable forming wire adapted to carry upon its upper surface. a layer of liquid saturated pulp, and a stationary member for acting continuously on the pulp to rcompress the same as it moves past the member, said member having liquid ducts therein, for the purpose set forth.

28. In a ber board making machine, in combination, a movable forming wire adapted to carry a layer of liquid saturated pulp, and a stationary member for acting continuously on the upper side of the pulp to compress the same as it passes the member; said member having a liquid escape duct therein in the form of a continuous slot substantially coextensive in length with the width of the moving pulp layer.

29. The method of fabricating a fiber board which comprises passing a liquid saturated layer of pulp on a forming wire through a compression means which permits escape of liquid from both surfaces thereof, and regulating the direct escape of liquid from one surface, for the purpose set forth.

30. The method of fabricating a liber board which comprises passing a liquid saturated layer of pulp on a forming wire through a compression means which permits escape of liquid from both surfaces thereof, and modifying the rate of direct escape of liquid from one such surface while the' pulp layer is in motion, for the purpose set forth.

31. In a ber board making machine, in combination, a horizontally disposed and movable forming wire and a chamber for maintaining a body of pulp stock under static pressure upon the forming wire, the upper portions of the side walls of the chamber being substantially vertically disposed and overhanging the wire and the lower portions of the side walls adjacent the edges of the wire being downwardly and outwardly inclined at angles of substantially 45 with the horizontal, for the purpose set forth.

32. The method of fabricating ber board which comprises continuously forming a pulp layer on the upper surface of a forming wire moving uniformly in one direction by passing' said forming wire beneath a pulp stock chamber containing a relatively large body of pulp stock, the carrier liquid passing through the wire and the fibers being intercepted thereby, and gradually compacting said ber layer as it emerges from beneath said chamber by passing the same beneath a stationary member downwardly and forwardly inclined with respect to the path of travel of the wire, with which member the upper surface of the pulp layer contacts and by which it is downwardly deflected, a portion of the liquid expressed from the ber layer due to the compacting operation passing upwardly through said member.

33. The method of fabricating fiber board which comprises continuously forming a liquid saturated pulp layer on the upper surface of a horizontally disposed forming wire moving uniformly in one direction, and subjecting said layer,

as it passes one point in its horizontal travel, to the action of compacting means whereby its thickness is gradually decreased and a large proportion of its contained liquid expelled, a part 

